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Questions tagged [hvac]

(Heating, Ventilating, and Air Conditioning) For questions about installing, repairing, and troubleshooting HVAC systems.

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1answer
12 views

First Co Air handler + Gas Hot Water boiler: Connect thermostat for gas or electric?

My apartment's mid-90s heating system consists of a gas-fired hot water heater feeding a First Co TAQ1824 air handler. The air handler has a fan and blows hot air through air ducts. The system is ...
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0answers
15 views

Thermostat Upgrade, furnace C-wire reading low voltage

OK so here is the scenario. Upgrading thermostat from dumb to smart (Ecobee). I've done 2 others in my house that required re-wiring so I have a good sense for what should be done but I'm stuck. My ...
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0answers
16 views

Controlling one FCU with two thermostats

I have a chilled water fan coil unit that will feed two areas, living and the bedroom. I want to control the FCU with two thermostats, one in the living and one in the bedroom, (preferably) in a ...
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1answer
17 views

Thermostat controller switch?

Would two thermostats be possible if a master control switch was in place. For example I leave one end of the house, throw the control switch, and set the thermostat at the other end of the house. (...
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0answers
40 views

How do you replace a reversing valve? [closed]

My heat pump works like a champ. It heats well and cools well. The reversing valve gets stuck occasionally during the winter months. I've contacted three separate hvac companies to get a quote on ...
2
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1answer
28 views

Connecting Common Wire from thermostat to Air Handler

My apartment has a central heating/cooling HVAC system consisting of a gas-fired hot water heater which feeds hot water to a First Co air handler for heating, and a rooftop compressor which feeds ...
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1answer
9 views

Heil furnace going from winter to summer

I will be ready to switch furnace from winter to summer tomorrow. It's a dual system/oil switches over at 32. What should it read on my honeywell thermostat when i switch it over. Help appreciated.
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1answer
14 views

Trane Furnace Fan Works, But Heater Won't Run

As stated, my heat isn't coming on. When this started: Everything has been all fine and dandy all winter. The other day I ran the fan only for a few hours without the heat. After this, my heat ...
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3answers
63 views

Furnace can’t keep up when set to ON but keeps up fine on AUTO. Is this normal?

I’m in a pretty cold state. It’s been below zero F quite often this winter. My furnace has not been keeping up and my house has gotten pretty cold. I got some space heaters to supplement. Furnace is ...
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1answer
38 views

Why doesn't my Trane rooftop furnace ignite?

I’m having problems with my Trane model Yc0060C3H0AA rooftop unit. My inducer motor comes on, my igniter lights up and I can smell the gas valve opening up but my burners will not light. Serial # ...
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2answers
2k views

What's the best tool for cutting holes into duct work?

I've cut a few supply and cold air returns into my main branches and it's been a PITA. Need to cut another 6" hole for a return, it's just standard rectangle ductwork, probably 14" wide x 10" high.
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1answer
58 views

Thermostat C Wire (Possibly Unconnected)

I purchased a Honeywell RTH6500 Wifi Thermostat, which requires a C wire. My old thermostat showed a connected blue C wire. However, it was battery-powered. If I removed the battery, the thermostat ...
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0answers
34 views

HVAC System Making a “Turning Over” While Heating

My HVAC system is running for a very short time, then turns off and then makes this turning over noise. It's a 10 year old Amana heating and air conditioning unit. The sound seems to be coming from ...
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2answers
69 views

Is there HVAC system to maintain air temperature, humidity and carbon dioxide level in the house? [closed]

I'm looking for a HVAC system or device which can maintain predefined air temperature, humidity and CO2 level in the house. It would be nice if such a system can be upgraded to scale it for more rooms/...
1
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1answer
23 views

Connecting Common Wire to Control Board

I have a heat pump and want to add a thermostat that requires a common wire. I have read through many threads that show how to add a wire but I already have a few extra in the bundle so its not so ...
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0answers
41 views

How do I stop the ticking noise coming from my furnace duct? [duplicate]

I've had some HVAC people here to look at the ticking noise coming from our furnace duct. One of them installed a brace on the piece in question. This seemed to make the ticking less frequent, ...
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0answers
24 views

Furnace blower cycles off then on

Upon a call for heat my gas furnace (1997 Coleman/Evcon model DGAT056BDD counterflow furnace) blower normally delays coming on for 90 seconds. It consistently runs for a few minutes, stops for 8 ...
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2answers
46 views

How much cooling is my mist maker humidifier causing?

Closely related to Does a humidifier cool the air? but with a different kind of humidifier, and I'd like to know exact numbers. First question: for the same production volume of vapor, does an ...
1
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1answer
49 views

need to connect a c wire to my furnace/air conditioner

I installed a nest with 5 wires, but the blue wire is not connected to anything on the 25-30 year old furnace. We tried connecting the blue wire to what we thought was a common terminal, but the ...
0
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1answer
14 views

High elevation non- pv Burnham boiler with Tejurland powerventer installed at sea level [duplicate]

I have a 203ncl-tei2 boiler installed in danvers Massachusetts. This town is at sea level, not 2000k miles up. This boiler also has a failed tejurland (universal control) powerventer motor on it that ...
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0answers
21 views

U.s. boiler / Burnham boiler alterations

i have a 203ncl-tei2 boiler installed in danvers Massachusetts. Regular elevation. This boiler also has a failed tejurland (universal control) powerventer motor on it that is only humming, not ...
2
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0answers
30 views

Why isn't my furnace igniting?

I noticed cold air from my Carrier 58SS furnace. The main burners were not lighting. The pilot flame was strong, but yellow. When I tapped on the gas valve, the pilot shut off. I removed the pilot ...
5
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2answers
469 views

Can I use a larger HVAC Hard Start kit than is recommended?

I've got a 2.5 ton HVAC system. I've been looking at adding one of the 5-2-1 Hard Start kits to reduce the wear on the system. I see that they have recommended sizes for 1-2-3 ton, 4 ton, and 5 ton ...
2
votes
1answer
31 views

Is a flexible coupling okay to use on an ABS furnace exhaust pipe?

I want to use a Fernco coupling for 2 inch furnace exhaust is it okay? The venting is ABS and runs low across a doorway. I want to be able to bring stuff by and replace the pipe 2 times a year.
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1answer
37 views

Where to connect Blue C Wire at old furnace?

I have looked at other responses and each layout is a little different. Looking to connect a Smart Thermostat and need to know where to connect the Blue wire at the Furnace. See the attached picture....
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1answer
29 views

Do new Air conditioning units require new pads?

Is a new pad required when an entire new central AC unit (inside, outside, ductwork, everything) is installed? Does the outside unit require anything around it when it’s in the backyard?
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2answers
21 views

Forced-air heater for old floor registers

I have an older home which used to be centrally heated by a furnace in the crawlspace, but has since been retrofitted with forced-air wall heaters: Some of the wall heaters are in inconvenient ...
0
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1answer
45 views

Half of furnace turned off?

I moved into this house about 10 years ago, I noticed on the furnace that one of the breakers for the electric coils is off with a note saying "Leave breaker off". After cleaning out the blower for ...
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2answers
64 views

Furnace continously shutting down due to lost or low flame sense (Rheem)

My furnace will run great for most of its cycle, but when it has almost reached the thermostat setting, I will hear it shut off, run the blower, then re-light. It will sometimes finally reach ...
0
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2answers
40 views

how to bypass an HVAC unit float switch (safe-t-switch)

rats keep chewing through the safe-t-switch wires even when I taped them up heavy. before I get rid of all rats I need to just bypass the float switch. at least then I can use the heat while I'm home.
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2answers
88 views

Goodman furnace flames out after 5 mins from cold start

Problem with Goodman Furnace flaming out. After it has been off for about an hour it will flame out after it starts and runs for 5-10 min before it satisfies themo setting. Restarts and finishes cycle....
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0answers
17 views

Nest E without common wire stuck in purge loop as soon as the Rheem heat furnace ignites

I have a honeywell hz432 and just installed a few NEST thermostats with a common wire and they seem to run fine. I added another NEST E thermostat, but this one didn't have a common wire, and when it ...
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0answers
22 views

hvac fan won't stop

My Hvac fan won't stop even after the desired heat is reached after the gas burning stops. I changed the furnace limit switch, no difference. Today I noticed there is an auxiliary limit switch on top ...
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2answers
47 views

Replacement draft inducer motor stopped working after 3 months

My Goodman GMNT060-3 furnace stopped turning on in October. The tech diagnosed a bad draft inducer motor, because the fan wouldn't spin freely and made a grinding noise when turned by hand. I replaced ...
0
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1answer
30 views

Ecobee install with AC system disconnected

My house which was purchased from a bank (foreclosure) was originally wired with both central air and heater (forced air). But when the previous owner left, he took the air conditioning unit. The ...
0
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1answer
44 views

HVAC York diamond 80 furnace A/C

So I have a York diamond 80 furnace and the motherboard burned out so Lowe’s came and replaced it. I’ve been using the heater because it’s winter right now but the other day I accidentally hit the ...
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4answers
64 views

Goodman Furnace short cycling because of high limit . Cant figure out why?

So just had a Brand new Goodman furnace and a/c installed before winter hit. As soon as heating season started i noticed it was short cycling and had a flash code of 4. I contacted the installer and ...
0
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1answer
34 views

High Limit Switch

my fan for clearing residual gas comes on and continues to run without starting the furance. The circuit board is flashing 4 times which means bad high limit. I replaced with a new one, ran for a few ...
0
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1answer
36 views

Millivolt fireplace turns on by the thermostat but will not shutoff

I inherited a freestanding direct vent fireplace and I'm trying to get it to work with a thermostat. It functions fine using the ON/OFF/PILOT switch but will not work with a thermostat. It is a SIT ...
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2answers
28 views

How can I wire the Humistat and Humidifier so that Humudifier runs only during heat cycle?

I have Honeywell Humidifier HE225A, Honeywell Thermostat TH6110D and Honeywell Humidistat H8908B all installed already. Now my Humidifier runs 24/7 wasting water because it is connected with the ...
0
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1answer
52 views

C wire - thermostat - not providing power

I'm replacing my old Honeywell thermostat with a new Wifi thermostat. My old/current one is battery powered and doesn't use the C wire. I found the C wire behind the plate. I connected the c wire to ...
0
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1answer
14 views

New Thermostat Won't Engage Plinth Heating in Kitchen Island

I have two plinth heaters on either side of my kitchen island. Since the rest of the house is hydronic, I presume that these are hydronic (there is a zone valve at the boiler) with electric fans ...
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0answers
12 views

I installed a honeywell WiFi thermostat, the primary heat runs the heat pump instead oh the gas furnace

I want to run the gas furnace, but the primary heat turns on the heat pump. If I turn up the thermostat several degrees, then the gas furnace comes on . In emergency settings, nothing happens. How do ...
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0answers
25 views

Gas Furnace Creaks When The Wind Blows

I have a Williams Forsaire Top Vent‎ gas furnace that creaks when a strong gust of wind blows. Could the venting be loose or not fitting right? Any ideas?
1
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1answer
57 views

Are these red lights on my Honeywell HZ432 why my bedroom isn't blowing in heat?

I just moved into a new multi-family house with central heat/AC and the 3rd floor bedroom doesn't seem to warm up very well. When the thermostat is on, I don't feel hot air blowing in from the vents ...
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1answer
20 views

Central heat doesn't always kick back on

I have a York stellar forced hot air natural gas central heat. Many times if the thermostat is set to say 70 it will turn off after reaching that temp but then wont always kick back on when it drops ...
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2answers
43 views

Upstairs room too hot - can I install a room-to-room fan to blow hot air back into the high-ceiling living room? [closed]

I'm in a narrow, vertical, townhouse style three story house. My upstairs bedroom gets too hot, and downstairs gets too cold. I found I could fix the downstairs problem by running the HVAC fan full ...
0
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2answers
36 views

Furnace wont start

I have a Goodman 2 stage furnace that won't start. GMV950905DXA It was running 2 days ago and then stopped. Outdoor Temp is now -20 and will drop to -34 tonight. LP in tank is at 65%. It won't ...
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0answers
19 views

HVAC unit keeps tripping breaker

had a short in the float switch wire( its all chewed up from rats) the short blew the 5A fuse . I spliced the wire and reattached it to its self in 3 places. this got it working but now its tripping ...
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0answers
18 views

Lennox G40UH furnace not turning on

With the lower panel door switch closed, the combustion air inducer comes on. It runs for a little while and then shuts down. Nothing happens in the meantime. The system was working fine until this ...